Professor Hamida Hammad, from Belgium, has been studying how children exposed to dust on dairy farms are protected against asthma and allergies, in the hope of creating a vaccine.

Her team found most children exposed to farm dust produced a protein called A20, which seemed to protect them from inflammation responses. Day-care centres are already being built on farms in Europe to ensure small children have exposure to farm material, she said.

Other theories are that developed countries are now too clean, vitamin D deficiencies, genetics, and gut inflammation. In actuality it is probably a combination of all of these factors.

What do you think? Have any theories on what’s causing the rise of allergies? Share them in the comments below!